This invention relates to a multilayer transducer array for transducing energy. More specifically, this invention relates to an array having energy transducing elements arranged in rows and/or columns in multiple layers. The transducing elements are used for detecting or providing energy in a desired form.
Various known arrangements have been used for detecting energy passing through a given area. Although such area detectors are generally planar, specific applications may use area detectors having curved surfaces. Regardless of the shape, such area detectors detect energy falling within a given area, either planar or curved. Usually, such area detectors provide information about the location of the energy falling upon the area detector. In other words, such area detectors often distinguish between energy falling on one part of the area detector and energy falling upon another part of the area detector. Such a determination of the location of the energy hitting the detector is necessary for use of the area detectors in imaging systems.
Imaging systems commonly use area detectors to provide an image of an object, person, or other thing of interest based upon energy received by the area detector. The energy detected by the area detector may have passed through an object of interest. For example, if the imaging system is for medical or industrial three-dimensional (3D) computerized tomography (CT), x-ray or similar imaging energy will have passed through an object of interest such as a workpiece or patient. Other imaging systems may receive energy which has been reflected by an object (workpiece, person, or other thing or things) of interest. Still other imaging systems may detect energy, such as infrared energy generated by a machine, human, or other animal, originating from the object of interest.
Area detectors often have an array of detecting elements arranged in rows and columns, but linear detectors with an array of detection elements arranged in a single row or column are sometimes used in imaging and other systems where it is necessary simply to detect energy along a given line.
In either a two-dimensional (i.e., elements in rows and columns) detector array or a linear detector used for x-ray or similar high energy imaging, increasing the thickness of scintillation material in the detecting elements will increase in the efficiency of detection. That is, a thicker slab of scintillation material will more efficiently convert high energy radiation like x-rays and gamma rays into visible light (which in turn is sensed by a charge coupled device, called CCD, camera or similar light sensing arrangement). However, increasing the thickness of the scintillator slab reduces the spatial resolution because the light spreads in the scintillator.
U.S. Pat. No. 5,059,800 issued Oct. 22, 1991 to Cueman et al., assigned to the assignee of the present application, entitled "Two-Dimensional Mosaic Scintillation Detector", hereby incorporated by reference, discloses a technique for dicing a scintillator into small elements with reflective material placed between the elements to reduce optical cross talk. This design greatly improved the spatial resolution of the detectors, but limits the thickness of the detector elements. Specifically, there are difficulties making very deep cuts in the scintillation material with a very fine kerf (i.e., a fine cut). For a given thickness of scintillation material, the kerf width or distance from one side of the cut to the other side of the cut (i.e., perpendicular to the direction of cutting or end-to-end direction of the cut) must have a certain minimum size. If the material thickness is increased to maximize efficiency of detection, the required increase in the kerf will, to some extent at least, decrease the efficiency of detection. In other words, x-rays or other high energy being detected may strike the space in between adjacent elements of the scintillator. Thus, the use of a mosaic of diced elements improves spatial resolution, but the detection efficiency may be degraded.